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A thin film of thermochromic VO2 was prepared on m-Al2O3 substrate using a radio frequency (RF) magnetron sputtering technique. The epitaxial growth of the monoclinic M1 phase of VO2 on the m-Al2O3 substrate was confirmed through synchrotron X-ray diffraction (XRD) measurements. The transformation of this monoclinic M1 phase into a rutile phase at ~68 °C was reflected in the temperature-dependent XRD measurements of the VO2 thin film. The temperature-dependent electrical resistance measurements of this sample also revealed an abrupt metal-to-insulator transition at ~68 °C, which is reversible in nature. Temperature-dependent X-ray absorption (XAS) measurements at V L-edge and O K-edge were performed to study the electronic structure of the epitaxial VO2/m-Al2O3 thin film during the metal-to-insulator (MIT) transition. [ABSTRACT FROM AUTHOR]

Nanocrystals can be produced as a dry powder for inhalation (DPIs) to deliver high doses of drug to the lungs, owing to their high payload and stability to the shear stress of aerosolization force. Furthermore, lipid-coated nanocrystals can be formulated to improve the drug accumulation and retention in lung. The present work involved the fabrication of paclitaxel nanocrystals using hydrophilic marine biopolymer fucoidan as a stabilizer. Thereafter, fabricated nanocrystals (FPNC) were surface-modified with phospholipid to give lipid-coated nanocrystals (Lipo-NCs). The nanocrystals were fabricated by antisolvent crystallization followed by the probe sonication. The lipid coating was achieved by thin film hydration followed ultrasonic dispersion technique. Prepared nanocrystals were lyophilized to obtain a dry powder of FPNC and Lipo-NCs, used later for physicochemical, microscopic, and spectroscopic characterization to confirm the successful formation of desired nanocrystals. In-vitro and in-vivo investigations were also conducted to determine the role of nanocrystal powder in pulmonary drug delivery. Lipo-NCs exhibited slower drug release, excellent flow properties, good aerosolization performance, higher drug distribution, and prolonged retention in the lungs compared to FPNC and pure PTX. Lipid-coated nanocrystals can be a novel formulation for the maximum localization of drugs in the lungs, thereby enhancing therapeutic effects and avoiding systemic side effects in lung cancer therapy. [Display omitted] • Sub-micron sized PTX loaded Lipo-NCs were prepared for pulmonary delivery. • The NCs exhibited improved dissolution due to ∼10-fold effective surface area. • Aerosolization performance revealed deep lung distribution capability of NCs. • Lipo-NCs showed superior lung accumulation with minimal systemic distribution. • Lipo-NCs is ideal for pulmonary delivery of PTX in localized lung cancer therapy. [ABSTRACT FROM AUTHOR]

• N+ ion implantation induced modifications in the VO 2 films were studied. • N+ ion implantation has resulted in downward shift in structural transition temperature. • VO 2 film with implantation dose of 1 × 1015 ions/cm2 N+ ions showed metal to insulator transition at room temperature. Modifications in the structural and electronic properties of VO 2 films induced by N+ ion implantation were investigated. VO 2 films prepared by radio frequency (RF) magnetron sputtering deposition on quartz substrate were subjected to the N+ ion beam with 55 keV at different fluences (1 × 1015 and 1 × 1016 ions/cm2). Compared with the pristine VO 2 film (Tc ∼ 342 K), structural and electrical phase transition temperatures were shifted around room temperature in the N+ ion implanted sample (fluence = 1 × 1015 ions/cm2). Furthermore, a higher fluence of N+ ions (fluence = 1 × 1016 ions/cm2) had significantly modified the crystalline structure of VO 2 thin film, and a metallic behaviour was clearly noticed in the entire temperature range between 240 K and 373 K under this study. N+ ion implantation effectively induces the changes in the electronic structure of VO 2 thin films, which are further confirmed by the X-ray absorption spectroscopy (XAS) measurements. [ABSTRACT FROM AUTHOR]

Transparent-flexible thermoelectric materials are attractive for future small-sized consumer electronics, the internet of things, and wearable devices. The microstructural evolution and subsequent thermoelectric properties of Ti 1%.at-doped ZnO thin films, grown on polyimide flexible substrates, are presented. The thin films were grown using radio frequency a magnetron sputtering method followed by annealing for 60 min at temperatures of 200–400 °C under vacuum atmosphere. Post-annealed films demonstrate a hexagonal Wurtize structure. It is found that the annealing helped to relax residual stresses in the thin films, subsequently leading to enhanced charge concentration, carrier mobility, mean free path, and density-of-states effective mass. The thin film, annealed at 300 °C, illustrates the highest power factor of the films measured at room temperature at 19.10 μW m−1 K−2. Further increases in the annealing temperature suggest Ti2+ diffuses into the ZnO lattice and in turn disturbs the crystalline structure; this results in a reduction of the power factor to 9.32 μW m−1 K−2 at an annealing temperature of 350 °C. [ABSTRACT FROM AUTHOR]

[Display omitted] • Flexible transparent In/Ga co-doped ZnO (IGZO) thin films were achieved to fabrication on polyimide (PI) substrates by RF-magnetron sputtering method. • The microstructural evolution with annealing processing are enhanced the power factor to be achieved to 16.9 μW m−1 K−2. • Uni-leg thermoelectric thin film modules of four elements as fabricated were achieved the maximum power generation was found 3.2 nW at ΔT = 120 K. Transparent-flexible thermoelectric thin films have immense potential as power supplies for future small-sized consumer electronics, the internet of things, and wearable devices. Here, we report the thermoelectric properties of dual Ga and In doped ZnO films (IGZO) deposited on a polyimide substrate with post-thermal treatment in vacuum along with fabricating 4-unileg flexible IGZO thermoelectric devices. All the as-deposited and annealed IGZO films are the preferred (0 0 2) orientation and under tensile stress. The post-thermal treatment controls the dopant substitution/diffusion in the host ZnO lattice affecting the film crystallinity, residual stress, and thermoelectric properties. Among the films, the IGZO film annealed at 250 °C has the best power factor of 16.9 μWm−1K−2 with the largest crystal size, lowest tensile stress, highest carrier concentration, and lowest density-of-state effective mass. The practical application of flexible IGZO films was also reported via a 4-unileg-IGZO films thermoelectric module, which achieved an output power about 3.2 nW at ΔT = 120 K. [ABSTRACT FROM AUTHOR]

In this work, homogeneous Ag-doped Sb 2 Te 3 (AST) thin films were prepared using the rf magnetron sputtering technique. Thermoelectric properties of AST films have been investigated in terms of various substrate rotation speeds (20, 40, 60, and 80 rpm) and rapid post-thermal treatments at 250 oCin a vacuum. It was found that the thickness of AST films decreases with the increase in substrate rotation speeds. An Ag atomic composition slightly increases and the other Sb and Te atomic compositions slightly decrease with the increase of substrate speed rotations. The post-thermal treatment improved film crystallinity. Carrier scatterings at the grain boundaries tend to increase the resistivity and the Seebeck coefficient. The maximum power factor of 4.60 mW m−1K−2 (ρ = 19 μΩm, S = 298 μVK−1) is obtained in the AST thin films prepared with the substrate rotation speed of 60 rpm. The practical application of AST films was also reported via a thermoelectric module of five p -AST/n-Bi 2 Te 3 thin-film pairs with its achieved output power of 1.6 nW at ΔT = 20 K. • Ag–Sb–Te (AST) thin films were fabricated by RF magnetron sputtering. • Substrate rotation speed at 60 rpm induced highly homogeneous and more uniformity of thin films. • Rapid thermal annealing has changed amorphous to crystalline thin films as well as microstructure and thermoelectric properties enhancing. [ABSTRACT FROM AUTHOR]

Pure CdO nanostructured thin films and Ag doped with 1.0, 2.0 and 4.0 wt% doping concentrations were fabricated successfully on glass substrates with a cost-effective spin coating technique. The prepared films exhibit a cubic crystal structure oriented along (111) plane. The surface morphology of the pure CdO films shows a cauliflower shape structure, becomes granular, and compact at high Ag doping concentration. Raman spectra of the films reveal LO (longitudinal optical) and TO (transverse optical) vibration modes at 406.80 cm−1 and 566.54 cm−1. The absorption of the films significantly varies with Ag doping concentrations and as a result, the electronic structure of the films is tailored. Moreover, the optical band gaps vary in the range of 1.42–1.70 eV. In addition, the optical parameters n, k were studied in correlation with Ag doping concentrations. The obtained room temperature photoluminescence spectra of the prepared films show a broad peak at ∼350 nm. The third order nonlinear optical parameters of the films were also examined systematically. • Cauliflower morphology of pure CdO films was observed as incorporation of Ag films morphology change drastically. • Interesting change in NBE peak was observed as incorporation of Ag in CdO films. • 4.0 wt% Ag doped CdO films reveals remarkable enhancement in third order nonlinear optical susceptibility. [ABSTRACT FROM AUTHOR]